Solving a beatis hatch: any suggestions?


Active Member
This past weekend I fished the Tevere, a tailwater in the Tuscany region of Italy. It has a large population of brown trout and grayling, is rich in insect life, and sees a lot of flyfisherman over the course of the year. So many people fish it that the trout (to a certain extent) have become "desensitized" to the presence of people, not spooking as one might expect when approached without proper stealth. They also have seen a lot of flies (mostly patterns designed to float on the surface or in the film as Italians in general rarely nymph).

This time of year, beatis mayflies constitute the primary hatch on the river, and both days we encountered consistent hatches that began in the late morning and would last until mid afternoon. Not being an entymologist, I am not exactly sure about this, but from the samples I collected on the stream, there appeared to be three different species/types of beatis mayflies hatching, each of which was of a different size and slighly different color. Throughout the day fish were rising to feed both on the duns and the nymphs just under the surface. I took two throat samples from fish I caught in two different sections of the stream and one of the fish had been feeding exclusively on duns, while the other had been feeding exclusively on nymphs(The duns and nymphs from the sample were all identical with each other in respect to size, color, shape, etc.) The riseforms of feeding trout indicated as much, as did simply watching one of the newly hatched baetis duns drift down the stream only to disappear in a swirling rise.

I spent a considerable amount of time in each section I fished closely inspecting the water, even getting right down to the surface to see what was floating downstream. I did not have a seine, although it would have been helpful in this situation I believe because there were what appeared to be a small number of tricos (spent) and some midge pupal shucks. From my observations and samplings, I deduced that the majority of fish were keying in on the beatis mayflies, and so I spent most of my time trying to "match" that hatch. The majority of visible surface feeding occured in long, broad flats, back eddies, or slow, deep pools as the water was cold and the fish were not holding in areas with significant flow/current.

The weather conditions were typical for a baetis hatch: cloudy and overcast with some light rain (that turned to heavy rain in the early evening) with brief periods of clearing such that it was partly sunny at times. Water clarity was not "perfect", as there was some discoloration but nothing significant.

When targeting these rising fish, I used a 15ft leader tapered down to 6x, with a couple feet of 7x tippet attached to the end of my leader (some of the Italians I spoke with recommended going as light as 8x, but I did not have anything that light). As far as approaches, I tried both upstream and downstream presentations, as well as cross stream presentations that required reach casts. Various slack line casts were also made from different angles in an attempt to minimize drag and allow the fly to be the first thing seen by the fish. I fished about every baetis imitation I had in my box that fit the size/color/profile of the naturals I collected and observed on the water. Parachute style patterns, no-hackle CDC patterns and sparkle duns, etc. all failed to produce consistently. Refusals were equivalent to getting a fish to take, particularly on Sunday when I caught one fish on a size 22 olive CDC pattern in close to 6 hours of fishing. I also tried fishing small wd-40s, rs-2s, pheasant tails, etc.. as a dropper off my dry/emerger pattern with no success. Though I did not try swinging soft hackles, I did try "twitching" the unweighted nymph directly back upstream just below the surface through the rising fish, again with no takers. Dead drifting nymphs shallow (mid depth to just below the surface) also produced nothing, as did dredging a two nymph rig along the bottom.

During the periods of concentrated feeding on or near the surface, I would pick out a fish and try to target it, as opposed to simply "flock shooting". The one fish I caught on Sunday was one I had targeted, trying to get a feel for its feeding rhythm. However, it was difficult to get a good read as the same fish would rise to feed more erratically than rythmically. I spent over an hour on one fish alone that seemed to be feeding this way, which made timing my presentation/drift difficult with its feeding "rhythm" difficult at best. The slow, flat water in some sections was fairly easy to manage for drag, but in other sections it was more difficult and micro-drag I suppose could have been an issue. Refusals were the order of the day, and changing tippet size, lenghening the leader, using different pattern styles (as well as adjusting color, size, and profile of the patterns), adjusting presentation angles, etc. all did not help.

With this background information in mind, does anyone have any suggestions on how to approach a situation like this? It was a great learning experience for me because I am primarily a nymph fisherman and this really forced me outside of my "comfort zone" to use some skills that still obviously need developing. It would have been great to have someone there to 'coach' me through that situation, which left me pretty dumbfounded as to what to do next. Maybe some of you can help me out as I am returning to fish this river again at the end of the month. Pace.



Active Member
I had a similar experience a few years ago on the Railroad Ranch section of the Henry's Fork. Several large rainbows were feeding below me. There were PMD's, baetis and flavalinea on the water. I emptied my box out in search of the fly that these bows would take. I finally found out what they were taking by focusing on a natural on the water and watching it drift down into the feeding lanes. If it wasn't taken, I picked a different fly and watched it. In the end, it was flavs that were lying on their sides. These were trout that were under heavy fishing pressure. They fed under multiple hatches and flyfishers and had become highly selective. They only rose to the crippled duns (not Quigleys, but "knocked down duns") amongst all the flies that came over them and here's the kicker, they moved at least 2-3 feet on either side to take them.

Hope this helps,


Active Member
Leland, that is a great observation and a terrific point. The fish I was working did the same thing -moving two or three feet to take a natural. This fish also would come to the surface from time to time and refuse something (not my fly) drifting on the surface that obviously was not exactly what he was looking for. I did exactly what you did, picking out a natural and watching it drift downstream, then watching another natural if the first one was not taken. I did fish a cripple imitation, but only briefly, and not on the second day. I had also read an article discussing the merits of fishing "flopped over" duns that were not drifting with their wings upright. I never thought of that in this situation (hindsight is 20/20!!) and it could have well been the "secret" to figuring out this situation. Do you have any pattern recommendations for fishing duns which are crippled or "knocked over"? I would love to tie some up before heading back at the end of the month. Thanks so much for the help.



Staff member

The Tuscany Region of Italy contains (18) Baetidae species including: Acentrella (1), Alaenites (1), Baetis (8), Centroptilum (1), Cloeon (2), Nigrobaetis (1), and Procloeon (4). This can be verified on my Italian Mayfly Distribution page. For purposes of comparison, that is at least three times as many Baetidae species as reside here in Washington.

To state the obvious, a lot of surface refusals means trout are actively feeding on the surface, and your fly is close enough to what they want, that they are interested enough to inspect it, but something isn't quite right, so they won't grab it. Although there are a multitude of possible causes for this behavior, lack of realistic dun tails is the one I would first suspect under the particular set of circumstances you so beautifully describe.

The pattern I suggest you try next time is a Comparadun tied with an extremely sparsely dubbed body, split (2) microfibit tails slightly longer than body length, and on a hook at least a size smaller that the dun appears to you as you see it fly off. Hope this helps.
BWO hatches on the Yakima can be frustrating at times, but it sounds like they are a piece of cake compared to your experience in Tuscany! I was fishing a nice hatch on the Yak one October a few years ago and thought I was doing pretty well, catching a handfull of nice fish, but the other fisherman on the same run was catching 3-4 fish for every one I caught. As the hatch was winding down and fish stopped rising, I took the opportunity to ask him what he was using. It turned out he was fishing a #26 midge imitation. It was clear that SOME fish were taking BWOs, but for every fish feeding on mayflies, there were several taking midges. I now often fish mixed mayfly and midge hatches with a dropper and a very small midge emerger trailing the larger mayfly imitation. There is no way my 55 year old eyes can see the midge pattern, but I set up on any rise near the fly I can see. I probably get 75% or more of the takes on the smaller pattern.


Stephen Mull
I second what Leland said. I have been in the same situation on a number of spring creeks (including the Ranch) and found that trout not only are feeding on one specific insect (when 2-4 are present). I have seen two different size PMD's coming off and fish only feeding on one size. Sometimes there may be a hatch going on and spinners falling at the same time and fish only taking the spent bugs. Leland's approach of selecting a fly as it drifts by you and watching the outcome is bueno. One thing I have noticed is that on spring creeks, when in doubt fish the smaller bug.


Active Member
Taxon, I did check out your Italian mayfly distribution page (very informative by the way!) before I fished the Tevere, although I am not knowledgeable enough to make species distinctions within the Baetidae family. Observation and throat samples allowed me to deduce which of the three species were being keyed on, but even with that information my imitations were not sufficient to get consistent strikes. You mentioned the split tails, and I fished two different pattern styles with split microfibbet tails. The one fish I took on Sunday hit a cdc pattern tied with such a tail, but I had numerous fish refuse the same fly in different parts of the stream.

I was wondering how important you think the wing configuration is on a pattern? In other words, when a trout is seeing a dun drift downstream, can its wings act as a visual key or trigger for the trout to feed on it (outside of duns which are crippled or "knocked down" and floating on its side - in those situations the wings of the natural seem obviously important). I was thinking that an upwing no hackle pattern (tied to resemble the sailboat shape of the mayfly) might have been a better option than using a parachute or cdc pattern. The impression or "footprint" of such a no hackle pattern (particularly in the type of water I was fishing) may more closely resemble that of the natural beatis duns floating on the surface that day. Not really certain about that, but I suspect the less hackle the better in situations like the one I was fishing. My parachute patterns could have been tied more sparsely with less hackle, although I was not using dubbed bodies, but bodies made of tying thread.

I will tie up more patterns with the split tail configuration, which I believe is important under such conditions where everything about your fly needs to be "perfect".


Staff member
dbk said:
... I was wondering how important you think the wing configuration is on a pattern?
Well, on slower relatively smooth water (like you described), where trout have ample opportunity to closely inspect the imitation, I believe it is important for the dun's body to be in actual depressional contact with the water, and of course, this generally requires the absence of traditionally wound hackle.

One of the reasons I particularly like the Comparadun pattern is that it successfully imitates both the dun and spinner. However, that is somewhat of a moot point with Baetis, as they typically dive underwater for purpose of oviposition.

In any event, in answer to your question about wing configuration, when fishing to fussy trout, it can be critical whether the wings are configured upright, partially spent, fully spent, or even "tipped over", as Leland astutely indicated.
Wow, these are the kinds of posts that keep me coming back to this site! Great discussion. Thanks to all.
I would agree with everything that is being said that observation and patience is the key. I would also add another often overlooked situation. Often I offer what my buddies and I call giving them candy. If they're eating size 20 Trics or BWO's the chance sometimes that they will eat yours amongst the thousands is sometimes asking a little much. So I go with a larger by a size or 2 or I do not know how many times I've seen finicky fish eat a small wulff or Trude. I use Quiglys and standard patterns like red quills often in these situations.


Sculpin Enterprises
Great conversation!!

Another suggestion is to fish a double fly setup, either a larger and smaller dry or a larger dry and an emerger/nymph. The first acts as a strike indicator for the second and may induce the occasional fish in the mood for steak. Also, I like the appearance of biot-bodied flied, more realistic than just dubbing alone. Problems of microdrag can be a real challenge too in complicated currents, but where fish still have a good look at the bugs. Some fish are in very tough locations; sometimes, it is more profitable to concede defeat and find fish in a more amenable location.



Active Member
Steve, I did try fishing the two fly system you described, but in hindsight I probably should have utilized it more than I did. It obviously allows me to imitate both the dun and the emerging nymph, and in some of the broader flats large pods of fish were feeding on both the duns and the emergers/transitional nymphs. However, I was concerned with drag, and in these flats which were "smooth" in appearance, they often were many complex, divergent currents flowing together that would take your fly off its natural, drag free line of drift pretty quickly (even when I was fishing without any fly line on the water, but simply the leader). It was difficult enough to fish one fly without drag, and I believed fishing a dropper off the back of my lead fly only would have complicated matters even more. Most of the larger fish were holding very tight to the banks, often under the streamside bushes, vegetation, etc,. As such, these holding lies did not give me much of a "window" to present the fly and get a drag free drift. It was frustrating to make the perfect cast into that small "window" only to have the trout refuse or outright ignore your fly altogether, particularly when these same fish were at times feeding vigorously on the naturals.

Biot bodies are great, but maybe you have some suggestions on how to maintain a slim abdominal profile on your patterns. When I am fishing small flies (20-24), I find it difficult to maintain such a profile when using biots, but I am a relatively new fly tyer and would be open to hear any suggestions you may have. Thanks for the ones you have already offered.
I fish some pretty selective fish that on waters that are hammered like your Italian fish during baetis hatches and find that simply going smaller, even smaller by one or two sizes than the naturals, often works. Some people wont go down to a 24 or 26, but it can be quite worth it. Also cripple patterns will work when others wont. Swinging wet flies is another popular method to get these picky fish.


Active Member
On heavy pressured fish it seems that the fish learn that the larger bugs often have hooks attached. On those days when there are multiple hatches I concur with lucky I typcially go with the smaller patterns first.

Had an interesting time on a couple of the spring creeks in the "driftless area" in SW Wisconsin with wild browns feeding in BWOs in the fall. Typically there would be 3 or 4 Mays hatching at once as well as midges and even the odd caddis. What was fun/frustrating was while the hatches would be similar through a given reach of stream the various pods of fish would be targeting different bugs. One pool all the fish would want a #20 spinner and the fish in the next pool would not touch that pattern but would take a different size fly or a dun or even a midge.

The drill got to be have a 1/2 dozen different patterns ready to go. I would pick a fish and after careful observation I would present the choosen fly numerous times and once I felt I had give the fish a 5 or 6 "good looks" (with drag free drifts) at the pattern I would change to my next best bet. Would end up rebuilding the leader due to all the fly changes - however being able to solve the problem was pretty satisfying.

When it got too frustrating I would typcially fall back to terrestrials. Small hoppers (14s) and ants (18/20s) were often the ticket or something completely out of the norm for most anglers which this case was crickets or beetles. While the terrestrials nearly always produced fish and often some large fish they were not quite as satisfying as solving the hatch puzzle.

Working on such hatches certainly filled my fly boxes as each difficult evening always resulted in another session at the fly tying table.

Tight lines
there is a CDC wing baetis that we were turned onto on lake Hebgen, that can do very well in the rivers as well, I personally do not like the materials water retention, meaning that you must have a rotating bullpen of this pattern, but it does work well